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Full-Text Articles in Life Sciences

Impact Of Introduced Parasitoid Cotesia Vestalis (Hymenoptera: Braconidae) On Plutella Xylostella (Lepidoptera: Plutellidae) And Its Parasitoid Guild On Kale In Semi-Arid Areas In Kenya, Ruth Kahuthia-Gathu, Brigitte Nyambo, Sevgan Subramanian Sep 2017

Impact Of Introduced Parasitoid Cotesia Vestalis (Hymenoptera: Braconidae) On Plutella Xylostella (Lepidoptera: Plutellidae) And Its Parasitoid Guild On Kale In Semi-Arid Areas In Kenya, Ruth Kahuthia-Gathu, Brigitte Nyambo, Sevgan Subramanian

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Cotesia vestalis was introduced into Kenya from South Africa in March 2003 for biological control of Plutella xylostella with initial release in 2004. To confirm establishment, the rate of spread beyond the release sites and parasitism rates by C. vestalis were assessed between October 2011 and April 2012 in eastern and southeastern Kenya (Kitui, Mwingi/Yatta and Loitokitok areas). Monthly observations on kale infestation by diamondback moth, damage scores, parasitism and parasitoid guild were undertaken on 20 randomly selected plants in farmer-managed kale farms. Sampled larval and pupal stages were placed in containers and taken to the laboratory for parasitoid emergence. …

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Organic Farming Provides Improved Management Of Plant Parasitic Nematodes In Maize And Bean Cropping Systems, Janet G. Atandi, Solveig Haukeland, George M. Kariuki, Danny L. Coyne, Edward N. Karanja, Martha W. Musyoka, Komi K.M. Fiaboe, David Bautze, Noah Adamtey Sep 2017

Organic Farming Provides Improved Management Of Plant Parasitic Nematodes In Maize And Bean Cropping Systems, Janet G. Atandi, Solveig Haukeland, George M. Kariuki, Danny L. Coyne, Edward N. Karanja, Martha W. Musyoka, Komi K.M. Fiaboe, David Bautze, Noah Adamtey

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Intensification of agriculture, combined with poor agronomic practices have increased the incidence of plant parasitic nematodes (PPN) and other soil pathogens in East Africa, which consequently affects crop productivity in small holder farms. The objective of the study was to assess the effectiveness of farming systems in management of PPN and to recommend the best practice to farmers. Therefore, two field trials were established, one in farmer fields and one on-station, using maize (Zea mays L.), intercropped with beans (Phaseolus vulgaris L.) and in rotation with beans as a sole crop. Organic farming (that received compost, Tithonia diversifolia and neem …

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Mapping Leaf Nitrogen And Carbon Concentrations Of Intact And Fragmented Indigenous Forest Ecosystems Using Empirical Modeling Techniques And Worldview-2 Data, Galal Omer, Onisimo Mutanga, Elfatih M. Abdel-Rahman, Kabir Peerbhay, Elhadi Adam Sep 2017

Mapping Leaf Nitrogen And Carbon Concentrations Of Intact And Fragmented Indigenous Forest Ecosystems Using Empirical Modeling Techniques And Worldview-2 Data, Galal Omer, Onisimo Mutanga, Elfatih M. Abdel-Rahman, Kabir Peerbhay, Elhadi Adam

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Forest nitrogen (N) and carbon (C) are among the most important biochemical components of tree organic matter, and the estimation of their concentrations can help to monitor the nutrient uptake processes and health of forest trees. Traditionally, these tree biochemical components are estimated using costly, labour intensive, time-consuming and subjective analytical protocols. The use of very high spatial resolution multispectral data and advanced machine learning regression algorithms such as support vector machines (SVM) and artificial neural networks (ANN) provide an opportunity to accurately estimate foliar N and C concentrations over intact and fragmented forest ecosystems. In the present study, the …

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An Assessment Of The Magnitudes And Factors Associated With Postharvest Losses In Off-Farm Grain Stores In Kenya, Joseph K. Mwangi, Christopher M. Mutungi, Soul Kifouly G. Midingoyi, Abdul K. Faraj, Hippolyte D. Affognon Sep 2017

An Assessment Of The Magnitudes And Factors Associated With Postharvest Losses In Off-Farm Grain Stores In Kenya, Joseph K. Mwangi, Christopher M. Mutungi, Soul Kifouly G. Midingoyi, Abdul K. Faraj, Hippolyte D. Affognon

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Off-farm grain storage is an important postharvest undertaking by government, traders and processors in Kenya. A survey was conducted in 2014/2015 to assess the kinds and magnitudes of perceived losses experienced in off-farm stores, and the factors associated with them. Store supervisors or key personnel charged with grain storage in 39 public and 74 private stores, spread across the six maize growing agro-ecological zones, were interviewed using a structured questionnaire. Total perceived losses averaged 17.6± 2.3%, and were attributed to insects (7.2± 1.0%), molds (5.7± 2.1%), moisture loss (3.4± 0.5%), rodents (2.0± 0.5%), spillage (0.50 ± 0.0%) and birds (0.10± …

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Quality Of Charcoal Produced Using Micro Gasification And How The New Cook Stove Works In Rural Kenya, Mary Njenga, Yahia Mahmoud, Ruth Mendum, Miyuki Iiyama, Ramni Jamnadass, Kristina Roing De Nowina, Cecilia Sundberg Aug 2017

Quality Of Charcoal Produced Using Micro Gasification And How The New Cook Stove Works In Rural Kenya, Mary Njenga, Yahia Mahmoud, Ruth Mendum, Miyuki Iiyama, Ramni Jamnadass, Kristina Roing De Nowina, Cecilia Sundberg

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Wood based energy is the main source of cooking and heating fuel in Sub-Saharan Africa. Its use rises as the population increases. Inefficient cook stoves result in fuel wastage and health issues associated with smoke in the kitchen. As users are poor women, they tend not to be consulted on cook stove development, hence the need for participatory development of efficient woodfuel cooking systems. This paper presents the findings of a study carried out in Embu, Kenya to assess energy use efficiency and concentrations of carbon monoxide and fine particulate matter from charcoal produced using gasifier cook stoves, compared to …

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Effect Of Insecticide-Treated Bed Nets On House-Entry By Malaria Mosquitoes: The Flight Response Recorded In A Semi-Field Study In Kenya, Jeroen Spitzen, Teun Koelewijn, W. Richard Mukabana, Willem Takken Aug 2017

Effect Of Insecticide-Treated Bed Nets On House-Entry By Malaria Mosquitoes: The Flight Response Recorded In A Semi-Field Study In Kenya, Jeroen Spitzen, Teun Koelewijn, W. Richard Mukabana, Willem Takken

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Insecticide-treated nets are currently a major tool to reduce malaria transmission. Their level of repellency affects contact of the mosquito with the net, but may also influence the mosquito's entry into the house. The response of host-seeking malaria mosquitoes approaching the eave of an experimental house was recorded within a large screen house. We compared entry- and exit rates in relation to the presence in the house of different insecticide-treated bed nets (ITNs) with an untreated net. Mosquitoes were lured towards the house by dispensing a synthetic host-odour blend from within the net in the house. Complementary WHO bioassays revealed …

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Application Of Secondary Nutrients And Micronutrients Increases Crop Yields In Sub-Saharan Africa, Job Kihara, Gudeta Weldesemayat Sileshi, Generose Nziguheba, Michael Kinyua, Shamie Zingore, Rolf Sommer Aug 2017

Application Of Secondary Nutrients And Micronutrients Increases Crop Yields In Sub-Saharan Africa, Job Kihara, Gudeta Weldesemayat Sileshi, Generose Nziguheba, Michael Kinyua, Shamie Zingore, Rolf Sommer

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Secondary and micronutrients are important in enhancing crop productivity; yet, they are hardly studied in sub-Sahara Africa. In this region, the main focus has been on macronutrients but there is emerging though scattered evidence of crop productivity limitations by the secondary and micronutrients. Elsewhere, widespread deficiencies of these nutrients are associated with stagnation of yields. Here, we undertake a meta-analysis using 40 articles reporting crop response to secondary and micronutrients to (1) determine the productivity increase of crops and nutrient use efficiency associated with these nutrients, and (2) provide synthesis of responses to secondary nutrients and micronutrients in sub-Sahara Africa. …

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Endemic Grasshopper Species Distribution In An Agro-Natural Landscape Of The Cape Floristic Region, South Africa, Samuel Adu-Acheampong, Michael J. Samways, Tobias Landmann, Rosina Kyerematen, Richard Minkah, Mukundi Mukundamago, Claude M. Moshobane Aug 2017

Endemic Grasshopper Species Distribution In An Agro-Natural Landscape Of The Cape Floristic Region, South Africa, Samuel Adu-Acheampong, Michael J. Samways, Tobias Landmann, Rosina Kyerematen, Richard Minkah, Mukundi Mukundamago, Claude M. Moshobane

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Conservation biologists and ecologists often make use of models to identify important biotic and abiotic factors that constrain species distributions for conservation decisions to be taken. In line with such practices, we developed species distribution models for four localized, Cape Floristic Region (CFR) endemic, flightless, congeneric Euloryma grasshopper species. We chose this group as use of these models has been little explored for narrow range endemics with specific traits. Euloryma larsenorum and E. lapollai are associated with fynbos only, while E. umoja and E. ottei are both associated with fynbos and vineyards. We used the Maximum Entropy algorithm, which showed …

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Vibrational Signals Of African Stingless Bees, K. Krausa, F. A. Hager, N. Kiatoko, W. H. Kirchner Aug 2017

Vibrational Signals Of African Stingless Bees, K. Krausa, F. A. Hager, N. Kiatoko, W. H. Kirchner

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Many bee species produce thoracic vibrations in various contexts. Among the social stingless bees (Meliponini) pulsed thoracic vibrations are used to communicate with nestmates. To date all studies on stingless bee vibrational communication have been conducted in the Neotropics. We, therefore, focused on six African stingless bee species of five genera: Meliponula, Hypotrigona, Liotrigona, Dactylurina, Plebeina. We analysed the signals’ temporal patterns. Vibrational signals appear to play a role in the recruitment of stingless bees. The degree of signal variation in the studied species was much lower than the variation in the signals of Neotropical stingless bees. Furthermore, the inter-signal …

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Vector Competence Of Populations Of Aedes Aegypti From Three Distinct Cities In Kenya For Chikungunya Virus, Sheila B. Agha, Edith Chepkorir, Francis Mulwa, Caroline Tigoi, Samwel Arum, Milehna M. Guarido, Peris Ambala, Betty Chelangat, Joel Lutomiah, David P. Tchouassi, Michael J. Turell, Rosemary Sang Aug 2017

Vector Competence Of Populations Of Aedes Aegypti From Three Distinct Cities In Kenya For Chikungunya Virus, Sheila B. Agha, Edith Chepkorir, Francis Mulwa, Caroline Tigoi, Samwel Arum, Milehna M. Guarido, Peris Ambala, Betty Chelangat, Joel Lutomiah, David P. Tchouassi, Michael J. Turell, Rosemary Sang

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Background: In April, 2004, chikungunya virus (CHIKV) re-emerged in Kenya and eventually spread to the islands in the Indian Ocean basin, South-East Asia, and the Americas. The virus, which is often associated with high levels of viremia in humans, is mostly transmitted by the urban vector, Aedes aegypti. The expansion of CHIKV presents a public health challenge both locally and internationally. In this study, we investigated the ability of Ae. aegypti mosquitoes from three distinct cities in Kenya; Mombasa (outbreak prone), Kisumu, and Nairobi (no documented outbreak) to transmit CHIKV. Methodology/Principal findings: Aedes aegypti mosquito populations were exposed to different …

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Assessment Of Risk Of Dengue And Yellow Fever Virus Transmission In Three Major Kenyan Cities Based On Stegomyia Indices, Sheila B. Agha, David P. Tchouassi, Armanda D.S. Bastos, Rosemary Sang Aug 2017

Assessment Of Risk Of Dengue And Yellow Fever Virus Transmission In Three Major Kenyan Cities Based On Stegomyia Indices, Sheila B. Agha, David P. Tchouassi, Armanda D.S. Bastos, Rosemary Sang

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Dengue (DEN) and yellow fever (YF) are re-emerging in East Africa, with contributing drivers to this trend being unplanned urbanization and increasingly adaptable anthropophilic Aedes (Stegomyia) vectors. Entomological risk assessment of these diseases remains scarce for much of East Africa and Kenya even in the dengue fever-prone urban coastal areas. Focusing on major cities of Kenya, we compared DEN and YF risk in Kilifi County (DEN-outbreak-prone), and Kisumu and Nairobi Counties (no documented DEN outbreaks). We surveyed water-holding containers for mosquito immature (larvae/pupae) indoors and outdoors from selected houses during the long rains, short rains and dry seasons (100 houses/season) …

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Why Organic Resources And Current Fertilizer Formulations In Southern Africa Cannot Sustain Maize Productivity: Evidence From A Long-Term Experiment In Zimbabwe, Tongai J. Mtangadura, Florence Mtambanengwe, Hatirarami Nezomba, Jairos Rurinda, Paul Mapfumo Aug 2017

Why Organic Resources And Current Fertilizer Formulations In Southern Africa Cannot Sustain Maize Productivity: Evidence From A Long-Term Experiment In Zimbabwe, Tongai J. Mtangadura, Florence Mtambanengwe, Hatirarami Nezomba, Jairos Rurinda, Paul Mapfumo

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Sustainability of maize-based cropping systems is a major challenge for southern Africa, yet the demand for maize as staple food and animal feed in the region continues to increase. A study was conducted on a sandy clay loam (220 g clay kg-1 soil) at Domboshawa in Zimbabwe to investigate the long-term effects of organic resource quality and application rate, and nitrogen (N) fertilization on soil chemical properties and maize (Zea mays L.) productivity. Crotalaria juncea (high quality), Calliandra calothyrsus (medium quality), cattle manure (variable quality), maize stover and Pinus patula sawdust (both low quality) were incorporated into soil at 4.0 …

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Drought-Tolerant Desmodium Species Effectively Suppress Parasitic Striga Weed And Improve Cereal Grain Yields In Western Kenya, Charles A.O. Midega, Charles J. Wasonga, Antony M. Hooper, John A. Pickett, Zeyaur R. Khan Aug 2017

Drought-Tolerant Desmodium Species Effectively Suppress Parasitic Striga Weed And Improve Cereal Grain Yields In Western Kenya, Charles A.O. Midega, Charles J. Wasonga, Antony M. Hooper, John A. Pickett, Zeyaur R. Khan

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The parasitic weed Striga hermonthica Benth. (Orobanchaceae), commonly known as striga, is an increasingly important constraint to cereal production in sub-Saharan Africa (SSA), often resulting in total yield losses in maize (Zea mays L.) and substantial losses in sorghum (Sorghum bicolor (L.) Moench). This is further aggravated by soil degradation and drought conditions that are gradually becoming widespread in SSA. Forage legumes in the genus Desmodium (Fabaceae), mainly D. uncinatum and D. intortum, effectively control striga and improve crop productivity in SSA. However, negative effects of climate change such as drought stress is affecting the functioning of these systems. There …

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Screening Napier Grass Accessions For Resistance To Napier Grass Stunt Disease Using The Loop-Mediated Isothermal Amplification Of Dna (Lamp), N. I.E. Wamalwa, C. A.O. Midega, S. Ajanga, N. E. Omukunda, F. N. Muyekho, G. O. Asudi, M. Mulaa, R. K. Zeyaur Aug 2017

Screening Napier Grass Accessions For Resistance To Napier Grass Stunt Disease Using The Loop-Mediated Isothermal Amplification Of Dna (Lamp), N. I.E. Wamalwa, C. A.O. Midega, S. Ajanga, N. E. Omukunda, F. N. Muyekho, G. O. Asudi, M. Mulaa, R. K. Zeyaur

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Napier grass stunt (NGS) disease is a major threat to Napier grass cultivation and the smallholder dairy industry in East and Central Africa. The disease is caused by a phytoplasma, which is transmitted by the leafhopper Maiestas banda (Kramer) (Hemiptera: Cicadellidae). The current study was conducted to identify among 65 Napier grass accessions that could be resistant to NGS disease using the loop-mediated isothermal amplification of DNA (LAMP). The accessions were caged with NGS phytoplasma-infected Napier grass as inoculum source and M. banda as the vector. All Napier grass accessions were subjected to phytoplasma testing thereafter 18 phytoplasma negative and …

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The Yield Gap: Closing The Gap By Widening The Approach, Katherine A. Snyder, Sriyanie Miththapala, Rolf Sommer, Juliet Braslow Jul 2017

The Yield Gap: Closing The Gap By Widening The Approach, Katherine A. Snyder, Sriyanie Miththapala, Rolf Sommer, Juliet Braslow

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The yield gap has arisen again as a focus for agricultural research to ensure food security and economic growth for farmers around the world. To examine this renewed interest, we carried out a review of key literature in the field of yield gap analysis to identify important gaps in research and analysis. In so doing, both the complexities in yield gap studies emerged along with some significant omissions. Much of the literature and research on the yield gap has been framed by larger concerns and initiatives to raise agricultural productivity. This focus has led to an emphasis on technical solutions …

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Advances In Crop Insect Modelling Methods—Towards A Whole System Approach, Henri E.Z. Tonnang, Bisseleua D.B. Hervé, Lisa Biber-Freudenberger, Daisy Salifu, Sevgan Subramanian, Valentine B. Ngowi, Ritter Y.A. Guimapi, Bruce Anani, Francois M.M. Kakmeni, Hippolyte Affognon, Saliou Niassy, Tobias Landmann, Frank T. Ndjomatchoua, Sansao A. Pedro, Tino Johansson, Chrysantus M. Tanga, Paulin Nana, Komi M. Fiaboe, Samira F. Mohamed, Nguya K. Maniania, Sunday Ekesi, Christian Borgemeister Jun 2017

Advances In Crop Insect Modelling Methods—Towards A Whole System Approach, Henri E.Z. Tonnang, Bisseleua D.B. Hervé, Lisa Biber-Freudenberger, Daisy Salifu, Sevgan Subramanian, Valentine B. Ngowi, Ritter Y.A. Guimapi, Bruce Anani, Francois M.M. Kakmeni, Hippolyte Affognon, Saliou Niassy, Tobias Landmann, Frank T. Ndjomatchoua, Sansao A. Pedro, Tino Johansson, Chrysantus M. Tanga, Paulin Nana, Komi M. Fiaboe, Samira F. Mohamed, Nguya K. Maniania, Sunday Ekesi, Christian Borgemeister

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A wide range of insects affect crop production and cause considerable yield losses. Difficulties reside on the development and adaptation of adequate strategies to predict insect pests for their timely management to ensure enhanced agricultural production. Several conceptual modelling frameworks have been proposed, and the choice of an approach depends largely on the objective of the model and the availability of data. This paper presents a summary of decades of advances in insect population dynamics, phenology models, distribution and risk mapping. Existing challenges on the modelling of insects are listed; followed by innovations in the field. New approaches include artificial …

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Returns To Research And Outreach For Integrated Pest Management Of Western Flower Thrips Infesting French Bean And Tomato In Kenya, E. A. Mujuka, H. Affognon, B. W. Muriithi, S. Subramanian, P. Irungu, J. Mburu Jun 2017

Returns To Research And Outreach For Integrated Pest Management Of Western Flower Thrips Infesting French Bean And Tomato In Kenya, E. A. Mujuka, H. Affognon, B. W. Muriithi, S. Subramanian, P. Irungu, J. Mburu

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Thrips, Frankliniella occidentalis (Pergande), is a major invasive pest that causes extensive yield losses in French bean and tomato in Kenya. Thrips management is based on the application of pesticides. In addition to increased environmental risks associated with pesticides, frequent use of these chemicals increases production costs and pesticide resistance. Furthermore, exports are restricted due to non-compliance to maximum residue levels in important consumer export markets, especially the European Union (EU). This study was conducted to estimate the potential benefits of the effectiveness of the icipe-developed strategy for control of western flower thrips before dissemination of the technology in Kenya, …

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Do The Mechanisms Modulating Host Preference In Holometabolous Phytophagous Insects Depend On Their Host Plant Specialization? A Quantitative Literature Analysis, Christophe Petit, Stéphane Dupas, Denis Thiéry, Claire Capdevielle-Dulac, Bruno Le Ru, Myriam Harry, Paul André Calatayud Jun 2017

Do The Mechanisms Modulating Host Preference In Holometabolous Phytophagous Insects Depend On Their Host Plant Specialization? A Quantitative Literature Analysis, Christophe Petit, Stéphane Dupas, Denis Thiéry, Claire Capdevielle-Dulac, Bruno Le Ru, Myriam Harry, Paul André Calatayud

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In holometabolous phytophagous insects, adult females and larvae determine host plant selection through oviposition and feeding preferences. Pre-imaginal and/or imaginal experiences with plant chemical cues can modulate these preferences. Various studies found evidence, or not, of host preference modulation through previous experience but they appear to contradict each other. Most probably, modulation of host preference depends on the degree of specialization of the insects. Our literature analysis revealed that the positive influence of experience in the modulation of host plant preference occurred equally in polyphagous, oligophagous and monophagous species, but was significantly more influenced by the phylogeny of the insect …

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Genetic Structure And Diversity Of Western Flower Thrips, Frankliniella Occidentalis In A French Bean Agroecosystem Of Kenya, P. Hondelmann, J. O. Nyasani, S. Subramanian, R. Meyhöfer Jun 2017

Genetic Structure And Diversity Of Western Flower Thrips, Frankliniella Occidentalis In A French Bean Agroecosystem Of Kenya, P. Hondelmann, J. O. Nyasani, S. Subramanian, R. Meyhöfer

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Western flower thrips (WFT) (Frankliniella occidentalis) is an introduced pest that harms French bean production in Kenya and other countries. Since new WFT management approaches are being developed, a closer look at the genetic makeup of WFT populations can give new insights into source habitats, crop colonization patterns or host plant preferences, which are prerequisites for integrated pest management (IPM) strategies. For this purpose, we used six microsatellite loci to analyse the genetic structure, diversity and gene flow of WFT sampled on French beans, intercrops and weeds in Kenyan French bean production areas. The results of this preliminary study indicate …

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Evaluation Of Onion (Allium Cepa) Germplasm Entries For Resistance To Onion Thrips, Thrips Tabaci (Lindeman) In Tanzania, Gabriel Michael Njau, Agnes M.S. Nyomora, Fekadu Fufa Dinssa, Jian Cheng Chang, P. Malini, S. Subramanian, R. Srinivasan Jun 2017

Evaluation Of Onion (Allium Cepa) Germplasm Entries For Resistance To Onion Thrips, Thrips Tabaci (Lindeman) In Tanzania, Gabriel Michael Njau, Agnes M.S. Nyomora, Fekadu Fufa Dinssa, Jian Cheng Chang, P. Malini, S. Subramanian, R. Srinivasan

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Onion thrips, Thrips tabaci (Lindeman), is a prominent species infesting onion and tomato in the northern highlands of Tanzania. It causes considerable leaf damage by direct feeding and also transmits the Iris yellow spot virus (IYSV). Hence, one of the objectives of this study was to identify the most resistant onion entries against T. tabaci. One highly resistant (VI038552) and two resistant onion entries (VI038512 and AVON 1067) were identified against T. tabaci. Besides thrips resistance, the bulb size of VI038512 was also equivalent to one of the commercial varieties, Texas. The highly resistant VI038552 recorded the highest yield, followed …

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Resolving The Taxonomic Status Of Frankliniella Schultzei (Thysanoptera: Thripidae) Colour Forms In Kenya - A Morphological-, Biological-, Molecular- And Ecological-Based Approach, M. W. Gikonyo, S. Niassy, G. B. Moritz, F. M. Khamis, E. Magiri, S. Subramanian Jun 2017

Resolving The Taxonomic Status Of Frankliniella Schultzei (Thysanoptera: Thripidae) Colour Forms In Kenya - A Morphological-, Biological-, Molecular- And Ecological-Based Approach, M. W. Gikonyo, S. Niassy, G. B. Moritz, F. M. Khamis, E. Magiri, S. Subramanian

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Frankliniella schultzei Trybom is a polyphagous pest and vector of tospoviruses worldwide. It occurs in dark and pale colour forms that are morphologically similar but differ in vector competency and geographic spread. In Kenya and other tropical regions, mixed populations of both colour forms are observed in similar habitats, so are considered as one species. To ascertain the taxonomic status of the two colour forms, they were characterized using morphological, molecular, biological and ecological approaches. Morphological characterization revealed differences between the colour forms on eight features and they separated into distinct clusters through principal component analysis. Restriction fragment length polymorphism …

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Molecular Detection Of Tick-Borne Pathogen Diversities In Ticks From Livestock And Reptiles Along The Shores And Adjacent Islands Of Lake Victoria And Lake Baringo, Kenya, David Omondi, Daniel K. Masiga, Burtram C. Fielding, Edward Kariuki, Yvonne Ukamaka Ajamma, Micky M. Mwamuye, Daniel O. Ouso, Jandouwe Villinger Jun 2017

Molecular Detection Of Tick-Borne Pathogen Diversities In Ticks From Livestock And Reptiles Along The Shores And Adjacent Islands Of Lake Victoria And Lake Baringo, Kenya, David Omondi, Daniel K. Masiga, Burtram C. Fielding, Edward Kariuki, Yvonne Ukamaka Ajamma, Micky M. Mwamuye, Daniel O. Ouso, Jandouwe Villinger

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Although diverse tick-borne pathogens (TBPs) are endemic to East Africa, with recognized impact on human and livestock health, their diversity and specific interactions with tick and vertebrate host species remain poorly understood in the region. In particular, the role of reptiles in TBP epidemiology remains unknown, despite having been implicated with TBPs of livestock among exported tortoises and lizards. Understanding TBP ecologies, and the potential role of common reptiles, is critical for the development of targeted transmission control strategies for these neglected tropical disease agents. During the wet months (April-May; October-December) of 2012-2013, we surveyed TBP diversity among 4,126 ticks …

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Evaluation Of Coloured Traps With Kairomone Attractant For Monitoring Thrips Population Dynamics On Tomato Crop In East Africa, Alexander Mutua Muvea, Helen Lydia Kutima, Zipporah Osiemo Lagat, Monicah Waiganjo, Sevgan Subramanian Jun 2017

Evaluation Of Coloured Traps With Kairomone Attractant For Monitoring Thrips Population Dynamics On Tomato Crop In East Africa, Alexander Mutua Muvea, Helen Lydia Kutima, Zipporah Osiemo Lagat, Monicah Waiganjo, Sevgan Subramanian

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Tomato is an important vegetable crop that is cultivated for the domestic market in Kenya and other East African countries. Thrips are one of the key pests hampering the production of tomato, both by direct damage to the crop and as vectors of tospoviruses. Field experiments were carried out over two planting times to evaluate the use of sticky traps for monitoring thrips infesting tomato in East Africa. Blue, yellow, and clear sticky traps with and without a thrips lure (Lurem-TR) were tested. Field observations for thrips catches on the sticky traps were made weekly until crop senescence. Sticky traps …

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Genotyping Of Theileria Lestoquardi From Sheep And Goats In Sudan To Support Control Of Malignant Ovine Theileriosis, A. M. Ali, D. A. Salih, M. N. Njahira, S. K. Hassan, A. M. El Hussein, Z. Liu, H. Yin, R. Pelle, R. A. Skilton May 2017

Genotyping Of Theileria Lestoquardi From Sheep And Goats In Sudan To Support Control Of Malignant Ovine Theileriosis, A. M. Ali, D. A. Salih, M. N. Njahira, S. K. Hassan, A. M. El Hussein, Z. Liu, H. Yin, R. Pelle, R. A. Skilton

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Theileriosis, caused by parasitic protozoa of the genus Theileria parasites, are among the major tick-borne diseases of ruminant livestock. The largest economic losses are attributed in particular to those caused by the leukoproliferative species of Theileria: T. parva, T. annulata and T. lestoquardi. Theileria lestoquardi is transmitted by Hyalomma ticks and causes malignant ovine theileriosis (MOT), a disease that is particularly prevalent in Sudan. The disease is considered of a high economic importance in Sudan, where export of sheep is a major component of the national economy. A live vaccine based on a Sudanese isolate of T. lestoquardi (Atbara strain) …

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Deinbollia Mosaic Virus: A Novel Begomovirus Infecting The Sapindaceous Weed Deinbollia Borbonica In Kenya And Tanzania, Martina Kyallo, Peter Sseruwagi, Robert A. Skilton, Mildred Ochwo-Ssemakula, Peter Wasswa, Joseph Ndunguru May 2017

Deinbollia Mosaic Virus: A Novel Begomovirus Infecting The Sapindaceous Weed Deinbollia Borbonica In Kenya And Tanzania, Martina Kyallo, Peter Sseruwagi, Robert A. Skilton, Mildred Ochwo-Ssemakula, Peter Wasswa, Joseph Ndunguru

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Four isolates of a bipartite begomovirus from naturally infected Deinbollia borbonica plants exhibiting yellow mosaic symptoms in Kenya and Tanzania were molecularly characterised. The DNA-A was most closely related to that of tomato leaf curl Mayotte virus (AM701764; 82%), while the DNA-B shared the highest nucleotide sequence identity with that of East African cassava mosaic virus (AJ704953) at 65%. Based on the current ICTV species demarcation criterion for the genus Begomovirus (≥91% sequence identity for the complete DNA-A), we report the full-length genome sequence of this novel bipartite begomovirus. The results reveal additional diversity and reservoir hosts of begomoviruses in …

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Predicting Stem Borer Density In Maize Using Rapideye Data And Generalized Linear Models, Elfatih M. Abdel-Rahman, Tobias Landmann, Richard Kyalo, George Ong'amo, Sizah Mwalusepo, Saad Sulieman, Bruno Le Ru May 2017

Predicting Stem Borer Density In Maize Using Rapideye Data And Generalized Linear Models, Elfatih M. Abdel-Rahman, Tobias Landmann, Richard Kyalo, George Ong'amo, Sizah Mwalusepo, Saad Sulieman, Bruno Le Ru

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Average maize yield in eastern Africa is 2.03 t ha−1 as compared to global average of 6.06 t ha−1 due to biotic and abiotic constraints. Amongst the biotic production constraints in Africa, stem borers are the most injurious. In eastern Africa, maize yield losses due to stem borers are currently estimated between 12% and 21% of the total production. The objective of the present study was to explore the possibility of RapidEye spectral data to assess stem borer larva densities in maize fields in two study sites in Kenya. RapidEye images were acquired for the Bomet (western Kenya) test site …

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Effect Of Organic And Conventional Farming Systems On Nitrogen Use Efficiency Of Potato, Maize And Vegetables In The Central Highlands Of Kenya, Martha W. Musyoka, Noah Adamtey, Anne W. Muriuki, Georg Cadisch May 2017

Effect Of Organic And Conventional Farming Systems On Nitrogen Use Efficiency Of Potato, Maize And Vegetables In The Central Highlands Of Kenya, Martha W. Musyoka, Noah Adamtey, Anne W. Muriuki, Georg Cadisch

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Increased per capita food production in the tropics is closely tied to soil organic matter and water management, timely nitrogen (N) supply and crop N use efficiency (NUE) which are influenced by farming systems. However, there is lack of data on the effect of organic farming systems on NUE and how this compares to conventional farming systems under tropical conditions. Therefore, the objectives of this study were to determine the effect of conventional and organic farming systems at low and high management intensities on N uptake and N use efficiency of potato (Solanum tuberosum L.), maize (Zea mays L.), cabbage …

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Ontogenetic Shift In Plant-Related Cognitive Specialization By A Mosquito-Eating Predator, Georgina E. Carvell, Robert R. Jackson, Fiona R. Cross May 2017

Ontogenetic Shift In Plant-Related Cognitive Specialization By A Mosquito-Eating Predator, Georgina E. Carvell, Robert R. Jackson, Fiona R. Cross

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Evarcha culicivora, an East African salticid spider, is a mosquito specialist and it is also a plant specialist, with juveniles visiting plants primarily for acquiring nectar meals and adults visiting plants primarily as mating sites. The hypothesis we consider here is that there are ontogenetic shifts in cognition-related responses by E. culicivora to plant odour. Our experiments pertain to cross-modality priming effects in three specific contexts: executing behaviour that we call the ‘visual inspection of plants’ (Experiment 1), adopting selective visual attention to specific visual targets (Experiment 2) and becoming prepared to respond rapidly to specific visual targets (Experiment 3). …

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Genetic Hitchhiking And Resistance Evolution To Transgenic Bt Toxins: Insights From The African Stalk Borer Busseola Fusca (Noctuidae), P. Campagne, C. Capdevielle-Dulac, R. Pasquet, S. J. Cornell, M. Kruger, J. F. Silvain, B. Lerü, J. Van Den Berg Apr 2017

Genetic Hitchhiking And Resistance Evolution To Transgenic Bt Toxins: Insights From The African Stalk Borer Busseola Fusca (Noctuidae), P. Campagne, C. Capdevielle-Dulac, R. Pasquet, S. J. Cornell, M. Kruger, J. F. Silvain, B. Lerü, J. Van Den Berg

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Since transgenic crops expressing Bacillus thuringiensis (Bt) toxins were first released, resistance evolution leading to failure in control of pests populations has been observed in a number of species. Field resistance of the moth Busseola fusca was acknowledged 8 years after Bt maize was introduced in South Africa. Since then, field resistance of this corn borer has been observed at several locations, raising questions about the nature, distribution and dynamics of the resistance trait. Using genetic markers, our study identified four outlier loci clearly associated with resistance. In addition, genetic structure at neutral loci reflected extensive gene flow among populations. …

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Unity In Defence: Honeybee Workers Exhibit Conserved Molecular Responses To Diverse Pathogens, Vincent Doublet, Yvonne Poeschl, Andreas Gogol-Döring, Cédric Alaux, Desiderato Annoscia, Christian Aurori, Seth M. Barribeau, Oscar C. Bedoya-Reina, Mark J.F. Brown, James C. Bull, Michelle L. Flenniken, David A. Galbraith, Elke Genersch, Sebastian Gisder, Ivo Grosse, Holly L. Holt, Dan Hultmark, H. Michael G. Lattorff, Yves Le Conte, Fabio Manfredini, Dino P. Mcmahon, Robin F.A. Moritz, Francesco Nazzi, Elina L. Niño, Katja Nowick, Ronald P. Van Rij, Robert J. Paxton, Christina M. Grozinger Mar 2017

Unity In Defence: Honeybee Workers Exhibit Conserved Molecular Responses To Diverse Pathogens, Vincent Doublet, Yvonne Poeschl, Andreas Gogol-Döring, Cédric Alaux, Desiderato Annoscia, Christian Aurori, Seth M. Barribeau, Oscar C. Bedoya-Reina, Mark J.F. Brown, James C. Bull, Michelle L. Flenniken, David A. Galbraith, Elke Genersch, Sebastian Gisder, Ivo Grosse, Holly L. Holt, Dan Hultmark, H. Michael G. Lattorff, Yves Le Conte, Fabio Manfredini, Dino P. Mcmahon, Robin F.A. Moritz, Francesco Nazzi, Elina L. Niño, Katja Nowick, Ronald P. Van Rij, Robert J. Paxton, Christina M. Grozinger

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Background: Organisms typically face infection by diverse pathogens, and hosts are thought to have developed specific responses to each type of pathogen they encounter. The advent of transcriptomics now makes it possible to test this hypothesis and compare host gene expression responses to multiple pathogens at a genome-wide scale. Here, we performed a meta-analysis of multiple published and new transcriptomes using a newly developed bioinformatics approach that filters genes based on their expression profile across datasets. Thereby, we identified common and unique molecular responses of a model host species, the honey bee (Apis mellifera), to its major pathogens and parasites: …

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